The present invention relates to a vehicle engine, and more particularly to an apparatus for cooling the engine compartment to protect various parts mounted therein from high heat.
Conventionally, an engine compartment cooling apparatus has been proposed which activates a fan to cool the engine when the temperature of the coolant for the engine rises above a predetermined value. In this circuit, voltage is supplied to an ignition line from a battery when an ignition switch is on. During engine operation, the temperature of engine coolant can increase to a predetermined value in which case a thermal-responsive switch is closed so that current flows from the battery through the ignition switch, the coil of a relay and the thermal-responsive switch to ground. This closes the contacts of the relay. As a result, current flows from the battery through the contacts and a fan motor to ground, thereby rotating the motor to cool the coolant and thus the engine compartment. During engine operation, the fan motor is controlled in an on-off manner by the thermal-responsive switch. In this apparatus, however, the fan motor is operated solely during engine operation so that the temperature of the engine compartment can temporarily exceed safe levels when the key switch is switched off immediately after high-speed travel, or high-load travel such as travelling up a slope or in hot summer. This is undesirable for parts such as those of relatively small thermal capacity or electronic parts susceptible to the influence of heat.